The invention concerns a system for detection and depiction of objects in the path of speedboats and other marine vessels, including warning about objects that may constitute a danger to navigation safety.
Increasing vehicle and vessel speed in passenger transportation, car transportation and goods traffic has increased the consequences from collision with floating objects. During recent years, the number of containers flushed overboard has increased significantly, and represents a high risk of accidents at sea in combination with drift timber and small leisure boats including certain whale species.
U.S. Pat. No. 5,465,142 describes a sweeping laser-radar-system for detection of obstacles to helicopters and other aircrafts. The laser-radar-technology per se is described relatively detailed in “IR/EO Systems Handbook”, SPIE, 1992.
Fast moving vessels are, in addition to radar, equipped with photosensitive video camera located as high as possible to improve overview of the water in front of the vessel. However, systems of this type are highly dependent on the light conditions and are not particularly useful when sailing at night in overcast weather.
During recent years, passive IR depiction based upon the FLIR (“Forward Looking Infra Red”) technology has been used for night vision and detection of drifting objects. This technique is based upon detection of small temperature differences between the object and the environments, and objects which have been in the sea for a long time may exhibit very small temperature difference and are therefore difficult to detect.
However, neither photosensitive camera nor IR systems are able to determine exact distances to objects within the view port.